We stayed in the 3rd unit of a 4-unit homestay building. The 1st unit is located on the ground floor if I'm not mistaken. So we just walked up 2 flights of stairs to get to our No.3 unit. There's one unit on each floor and there's no elevator, so be prepared to carry your luggage up.
The homestay is located in an alley behind the Brunei Embassy, and the area feels relatively safe. We walked in and out of the alley most of the time, with no issue. There's also a 7-Eleven; a cute cafe, Ink & Lion; and a massage parlour, Golden Massage @ Somerset Ekkamai Bangkok; just 3 minutes away from this Airbnb unit.
It came as listed, and was. spacious and clean. In the bathrooms, the water was hot and the water pressure was relatively strong as well.
The host was easily contacted when we had questions and was very helpful.